Stamps and stamp pads have been widely used heretofore because figures such letters, symbols, graphics, etc., can be reproduced easily by stamp imprinting. Stamp pads usually consist of a single color, such as black, red, or blue, and are primarily used for office applications.
In contrast to such single-color stamp pads, multicolor pad stamp pads in which a number of colored pads with different colors are arranged in a line have become commercially available in recent years. FIG. 11 is a schematic cross sectional view that illustrates an example of a conventional multicolor stamp pad. As shown in the figure, with a conventional multicolor stamp pad, a depression (22) is formed on a base (21). To the aforementioned depression (22) are adhered a line of colored pads (23) of different colors, obtained by allowing ink holders that are sponges (20) to absorb liquid pigment-based inks having a certain level of viscosity and thixotropy. The aforementioned colored pads (23) are fastened so that their tops protrude from the base (21). The tops of the colored pads (23) are covered by a lid (24). In addition, a groove (25) is formed around the base (21). Thus the edge surrounding the lid (24) can be joined to the aforementioned groove (25) to close the lid in a freely attachable and detachable manner.
When the aforementioned multicolor stamp pad is to be used in imprinting a rubber stamp that is smaller than the colored pads, it is possible to imprint the stamp in the desired color by selecting the color from the colored pads in multiple colors. If, however, the rubber stamp is larger than the colored pads, the rubber stamp is lightly pressed against the colored pads in multiple colors to ink it, after which the stamp is applied to the desired object (e.g., paper). Thus a single graphic on the rubber stamp can be printed in multiple colors. For example it is possible to obtain images consisting of a variety of different colors, such as a rainbow. This is especially popular with women and children.
Because liquid pigment-based inks are used on the multicolor colored pads consisting of various colors on the conventional multicolor stamp pad described above, the ink will not shift among the various colored pads even if adjacent colored pads touch each other directly. Thus the inks are never mixed together.
However, with the aforementioned multicolor stamp pad, if aqueous dyebased inks in particular are used and colored pads adjacent to each other make direct contact, ink will shift between the adjacent colored pads. As time passes the movement of ink back and forth causes the colors on the colored pads to change. As a result the original colors cannot be maintained.
In order to solve the problems that occur when such aqueous dye-base inks are used, adjacent pads have heretofore been separated from each other by various methods.
For example, as shown in FIG. 12, the individual colored pads (23) on the multicolor stamp pad can be partitioned using a plastic partitioning plate (26). This prevents the inks from mixing with each other. When the pads are to be used the aforementioned plastic partitioning plate is removed. With this method, however, removing the plastic partitioning plate is bothersome. In addition, after the plastic partitioning plate is removed spaces remain between the colored pads. This is problematic in that in some areas no color is applied in cases where a multicolor stamp image is to be imprinted.
In addition, there are multicolor pad stamp pads in which colored pads consisting of two colors are situated in small separate containers; these two containers are housed in the stamp holder base, and the individual colored pads are partitioned from each other by the walls on the small containers. This method, however, is problematic in that only a small number of colored pads are housed in the stamp holder, and multicolor stamp images cannot be imprinted because the colored pads are partitioned by the walls of the small containers.